A mechanical quantity measuring device can be attached to an object to be measured and thus can measure a mechanical quantity acting on the object to be measured. As this mechanical quantity measuring device, a device which uses a sensor chip applying an effect of resistance that varies depending on the strain (piezoresistive effect) is proposed. An impurity diffused resistor is formed on a surface of this sensor chip and the sensor chip is attached to an object to be measured, with an adhesive. When a mechanical quantity acts on the object to be measured and the object to be measured is strained, the impurity diffused resistor is strained via the adhesive and the resistance thereof changes. Therefore, this change in resistance can be outputted as a sense output and the mechanical quantity (strain) acting on the object to be measured can be detected.
In order to achieve widespread use of this sensor chip, it is important that the sensor chip can be easily attached to an object to be measured and that a sense output can be taken out securely. In response to such demand, a mechanical quantity measuring device in which a sensor chip is deposited on a flexible wiring board having a wire and in which the sensor chip is electrically connected to the wire, is proposed (see PTL 1 and the like). By thus forming a module including the sensor chip and the flexible wiring board, the device can be easier to handle than in the case where the sensor chip is provided singly.